I'm also curious to know what this means.
Wants and Nots could just mean more Likes/Dislikes, like favorite Foods, flowers, décor etc. It could also be a proper Want/Fears system like the Sims 2, maybe they're redoing Whims completely.
Wants and Nots could also be a hint towards an attraction system as well. An Attraction system could be built out of the Likes/Dislikes system.
I'm not sure how a Memory system would work. Would they just be Sentiments that last longer? I'm hoping they can make some type of Memory system before the Sims 4 is over.
I hope they announce something during the Livestream!